ABSTRACT Growing momentum and an ever-increasing body of evidence indicates that gene editing will become a standard treatment in therapeutic settings. Although proof-of-principle and validation projects have demonstrated activity in cells and to some degree, in animal models, more work needs to be done in characterizing the activity of various gene editing modalities. The development of mouse models will greatly accelerate our goal to bring gene editing to the clinic, helping to ensure a safer and more efficacious treatment. This proposal describes our plan develop reporters to allow facile and quantitative evaluation of all gene editing embodiments in an ?all-in-one? mouse that when edited, brightly and robustly provide a fluorescent, luminescent, and visual stain. For the most part, these reporter lines use conventional published approaches, incorporating best-in-class elements. Importantly the most complex aspects of these reporters have already been developed and tested in preliminary experiments. Our labs (coincidentally) have already been working in this space and construction of many of the proposed lines including validation controls have either been made or are already under way. As such we expect to have some as deliverables prior to, and at the latest, during Year One. Equally importantly, this proposal builds on extensive team-driven expertise, resources, and leadership skills of the two established University of California PIs located at UCD (Lloyd) and UCSF (McManus). Our partnership brings a significant strength to the SCGE Consortium, and we have assembled an excellent team of highly experienced team members and an exceptional Internal Advisory board to advance the program forward. Consequently, we see little ramp-up time needed to achieve the milestones associated with this award.